The effect of multiple exchange transfusions on bilirubin binding.

Three bilirubin binding tests (hydroxybenzene-azobenzoic acid dye binding method, the estimation of unbound bilirubin by horseradish peroxidase assay and the saturation of albumin by the salicylate saturation index) were performed on pre-exchange samples of blood and repeated 24 hours after the procedure. No significant improvement in bilirubin binding was found even in infants receiving as many as four exchange transfusions. Based on these bilirubin binding tests, we find no evidence that the criteria for subsequent exchange transfusions should be different from the first exchange transfusion.